Electric connector.



' E. B. WELCOX.

ELECTRIC CONNECTORr APPLlc/moN FILED ocr. 14'. 1915.

Pahd oct. 17,1916.

anser? is. Winona, or iannnnn, CONNECTICUT.

- atacante commercie.

ascissa'.

- roazzaattaaayaaacaaf `rnea ranas, that I, kknaam n. wanna. a citizen'of the.' United States olf-America, residing at l/leiulden,x 'Cnnecticut, have invented a new' and useful Electric Connector, otwhich .the following is 'a specitication.

` My present invention vaims toprovide a simple; practical and inexpensive form of plug connection can .be used interchangeably in sockets oi either' 'thet-wo wire or insulated, or the crie wire' grounded systems `ot electrical distribution.

In former' applicatonot mine, I have described and claimed a form of interchangeable plug connection having end terminals which coperatie with the contacts vof a two wire socketv anda side contact which comes into serviceI when the plug visinserted in a one wire socket, and which is electrically connected with one of the end terminals. This side contact is on the grounded side of the line and so, to avoid grounding of the circuit' at this point, the so called grounding connection between said side contact and the end terminal is made readily severable or disconnectible, so that the grounding connection can be broken when the plug is to be used in a two wire or insulated system.

A special object of this invention is to insure the interruption of this grounding connection when the plug is used in a two wire system. This object l have accomplislied by making the plug with two end terminals for engagement vwith the contacts of `-a two wire socket and a side Contact which isnormally disconnected from said terminals, and by furnishing with the plug a small connection or bridging member which can be plugged 'in to connect one of the end terminals with the side contact when the plug is to be used in a one wire system.

`This connecting device' takes the "form, in

the present disclosure, of a U-shaped metal clip, whose arms are engageable in recesses in the body of the plug and make contact with one end terminal and with the side Contact. 1

@ther `features and the details of structure will' appear as the specification pro ceeds.

changes and modifications may be gmade Specification of Letters Patent.l

y Patented (let. 1'?, i916.

A.ampueatima aieaoetober 1a, una serial' No. 55,835.

without departing from. the true spirit and scope of the invention.

. lathe drawing: Figure 1 is a', perspectiveview,y of the invention embodied in a lamp baseconstruction and a socket suitable for receiving the same, the grounding connec.- A

vtion or 4clip being shown detached and' at one sideo thelamp base.. Fig. 2 is a lonygitudinal sectional view showing the lamp inserted in a socket of the two wire type, the c1rtuit connections being illustrated dia-` grammatically. Fig. 3 is a similar view showingthe lamp associated with a socket of the one wire or grounded type. Fig. 4 is a perspective and more or less diagrammatic representation of the metal base of the lamp whichprovides the side contact,' .the end terminals and the grounding clip,

illustrating the relation of the several parts.

In they form of the invention illustrated, the base of the lamp constitutes the body of the plug connector and the same is shown in so that these two end contacts serve as the terminals of the lamp filament.

the form of a metal .shell or sleeve L in as indicated particularly in Figs. 1, 2 and 4,

A center contact 15 is provided for en I gagement with the center contact of the one wire type of socket, and this center Contact is electrically connected with one of the end 'contacts or terminals, in this-case the contact 11. f

When the lamp is to be used in a one wire type of socket, the other one (10) of the two end contacts, is electrically connected with the side contact 7 by means of a detachable bridging piece This bridging piece consists, in the present embodiment of the invention, of a strip of metal doubled upon itself in U-form to provide parallel arms 18 and 19 arranged one to engage with the end contact and the other to connect with the side contact.

In the illustration the end contacts and center Contact are Amounted on an insulating base securedto the end of the shell, this insulating' base being in the form of two disks 20 and 2l secured to the end flange 22 of the shell by holding clips 23 carried .by the llange and extended through the insulating disks and bent over at the outside to hold said disks in place.

The end contacts 10 and 11 are shown as strips of sheet metal having their ends passed through the outer disk 2O and clenched under as indicated at 25 and. 26 in Fig. et, to secure said contacts in place, and the "center contact 15 is shown as an integral extension of the end contact 11 having its end passed through and clenched under the outer disk, as indicated at 27.

i The inturnedends 25 of the end terminal 10 and the end llange 22 of the side contact27 constitute convenient contact surfaces for engagement by the arms of the bridging or grounding clip 17, andsaid clip is, therefore, used in the present illustration by inserting it over the edge of the inner disk 21, the one contact arm 18 being thereby engaged with one of the inturned securing portions 25 of the end contact 10, and the other contact arm 19 being thereby engaged with the end flange 22 of the shell. This inner insulating disk 21, therefore, serves to mechanically and electrically separate the end contact from the flange of the side contact, and the clip, therefore, serves as a member to4 be used when desired for electrically bridging the end contact and the side Contact. f

A socket suitable for use with the plug is illustrated at 30, Fig. 1, this socket being of the well known bayonet slot construction much used in automobile lighting systems.

The application of the invention to a two wire system is illustrated in Fig. 2. Here the socket 31 carries two contacts 32 and 33 disposed on opposite sides of the center line of the socket and arranged to be engaged by the two end contacts 10 and 11 on the plug.

In the grounded type of socket shown at 35 in Fig. 3, one side of the line is grounded as indicated at 36 on the socket body thereby constituting the body of the socket the one Contact, and the other contact is provided by a centrally located contact member 37. When the plug is to be used in this one wire type of socket, the clip is inserted in theside of the plug so as to electrically connect the end contact 10,and the side contact 7. rIhe current flow is in this case, from the center contact 37 of the socket to the center contact 15 of the plug, the end contact 11 with which sa'id center contact is electrically connected, through the lead wire 13, filament 9 and lead Wire 12 back to the other end con? tact 10, thence through the bridging clip 17, end flange 22, side contact 7 to the grounded socket shell 35.

The grounding clips are preferably so made and litted that they will naturally hold themselves in position connecting the end contact with the side contact, so that the lamps can be marketed either with or without the clips in position. A preferred method, however, is to sell the lamps with the clips detached and separate, the lamps in such case being ready for use in a two wire circuit, and capable of being made ready for use in a one wire circuit by simply inserting the grounding connection in the side of the plug. By disposing of the plugs in this latter way, the grounding of' the plug in a two wire circuit is guarded against because the plug is sold ready to be used in a two wire system, and the grounding clip must be inserted before it can be used in a one wire system.

W'hat I claim is:

1. In an electric plug, a metallic shell having. an end flange, an insulating base on said plug beyond said end llange, two exposed end contacts on said insulating base disposed on opposite sides of' the centerof the shell, a center contact on the insulating4 base electrically connected with one of said end contacts, and a bridging contact detachably engaged with the end flange of the shell and with the other one of the end contacts.

2. In a plug and socket connection, a plug member, two exposed end contacts on the end of said plug member disposed on opposite sides of the center thereof, a center contact electrically connected with one of said end contacts, a side contact on thev plu having a flange extending beneath the other one of the end contacts, said flange being separated from and electrically insulated from said end contacts anda metallic bridging member insertible in the space between said 4flange and said end contact and engaging said flange and end contact to electrically connect the same.

3. In a plug and socket connection, a metallic shell having an end flange, an insulating base carried by the end ci said shell, two end contacts mounted on said insulating base and disposed on opposite sides of the center of the shell, a center contact on said insulating base electrically connected with one of said end contacts, and a 'metallic bridging piece insertible in between the end flange of the shell and the insulating base and engageable with the other one of the end contacts to thereby electrically connect the end contact andthe end flange" g ioo c lilt` insertible over the edge of the innermost disk having side arms arranged one end contacts on said insulating base disposed on. opposite sides of thevcenter of the shell, a center 4contact on said insulating base electrically connected with one of the end contacts, and a bridging contact insertible at the sideof the insulating .base into engagement With the end flange of the shell and the other one of the end contacts.

6. In a plug construction of the character described, an insulating base, two exposed end contaes on the end of said base disposed onV opposite sides of the center thereu of, a center contact electrically connected With one of said contacts, a side contact having a contact .portion relatively closely approached to the' other one of the end contacts, but electrically separated therefrom, said insulating base having a space between said last mentioned end Contact and the contact portion of the side contact, and a bridging 'member insertible into said space into engagement with the Contact portion of the side contact and the said end contact.

nDsoN n. WILooX. 

